Towards Systemic Risk Aware Engineering of Large-Scale Networks: Complex Systems Perspective

摘要

This paper proposes a framework for systemic risk aware engineering of large-scale networks. Economics drives two major evolutionary trends in networked system design/operation: (a) towards the boundary of the system capacity/operational region, where all system resources are fully utilized, and (b) an increase in the system interconnectivity allowing enlargement of this region due to dynamic resource sharing. However, numerous recent systemic failures in various performance oriented networked systems demonstrated systemic risks associated with these trends. Using the "Complex System" perspective, we associate the systemic risks with a possibility of system phase transition to an undesirable persistent state. Specifically, we argue that while growing interconnectivity allows a system to accommodate "small" demand/capacity imbalances, sufficiently large imbalances may result in abrupt/discontinuous instabilities, which is a form of "robust yet fragile" phenomenon. Motivated by higher performance losses and lower predictability of abrupt/discontinuous vs. gradual/continuous systemic overload, the proposed "systemic risk aware performance engineering," intends to enlarge the system capacity/operational region subject to ensuring gradual/continuous system performance deterioration once the boundary of the system operational region is breached.